Determination of thiol/disulphide homeostasis in type 1 diabetes mellitus and the factors associated with thiol oxidation

Thiol reductive stress activates the hypoxia response pathway

Owing to their capability to disrupt the oxidative protein folding environment in the endoplasmic reticulum (ER), thiol antioxidants, such as dithiothreitol (DTT), are used as ER-specific stressors. We recently showed that thiol antioxidants modulate the methionine-homocysteine cycle by upregulating an S-adenosylmethionine-dependent methyltransferase, rips-1, in Caenorhabditis elegans. However, the changes in cellular physiology induced by thiol stress that modulate the methionine-homocysteine cycle remain uncharacterized. Here, using forward genetic screens in C. elegans, we discover that thiol stress enhances rips-1 expression via the hypoxia response pathway. We demonstrate that thiol stress activates the hypoxia response pathway. The activation of the hypoxia response pathway by thiol stress is conserved in human cells. The hypoxia response pathway enhances thiol toxicity via rips-1 expression and confers protection against thiol toxicity via rips-1-independent mechanisms. Finally, we show that DTT might activate the hypoxia response pathway by producing hydrogen sulfide. Our studies reveal an intriguing interaction between thiol-mediated reductive stress and the hypoxia response pathway and challenge the current model that thiol antioxidant DTT disrupts only the ER milieu in the cell.

Reactive Sulfur Species in Human Diseases

Significance: Reactive sulfur species (RSS) have been recently recognized as redox molecules no less important than reactive oxygen species or reactive nitrogen species. They possess regulatory and protective properties and are involved in various metabolic processes, thereby contributing to the maintenance of human health. It has been documented that many disorders, including neurological, cardiovascular, and respiratory diseases, diabetes mellitus (DM), and cancer, are related to the disruption of RSS homeostasis. Recent Advances: There is still a growing interest in the role of RSS in human diseases. Since a decrease in hydrogen sulfide or other RSS has been reported in many disorders, safe and efficient RSS donors have been developed and tested under in vitro conditions or on animal models. Critical Issues: Cardiovascular diseases and DM are currently the most common chronic diseases worldwide due to stressful and unhealthy lifestyles. In addition, because of high prevalence and aging of the population, neurological disorders including Parkinson's disease and Alzheimer's disease as well as respiratory diseases are a formidable challenge for health care systems. From this point of view, the knowledge of the role of RSS in these disorders and RSS modulation options are important and could be useful in therapeutic strategies. Future Directions: Improvement and standardization of analytical methods used for RSS estimation are crucial for the use of RSS as diagnostic biomarkers. Finding good, safe RSS donors applicable for therapeutic purposes could be useful as primary or adjunctive therapy in many common diseases. Antioxid. Redox Signal. 39, 1000-1023.

Dynamic Thiol-Disulfide Homeostasis in Lung Transplant Recipients

OBJECTIVES

In this study, we investigated dynamic thiol-disulfide homeostasis as a new indicator of oxidative stress in lung transplant recipients. In addition, we compared dynamic thiol-disulfide homeostasis parameters according to transplant indication and time after transplant.

MATERIALS AND METHODS

This study had a single-center, observational, randomized design. In terms of transplant indications, lung transplant recipients were grouped as chronic obstructive pulmonary disease, interstitial lung disease, bronchiectasis, and other indications. To make comparisons based on time after transplant, lung transplant recipients were categorized into the following groups: >6 and ≤24 months, >24 and ≤48 months, >48 and ≤72 months, and >72 months. A fully automated spectrophotometric technique was used to measure dynamic thiol-disulfide homeostasis in fasting blood samples.

RESULTS

Our study included 34 lung transplant recipients and 36 healthy volunteers. Native thiol (P = .005) and total thiol levels (P = .06) were lower in lung transplant recipients. Disulfide levels were similar. Disulfide-to-native thiol (P = .027) and disulfide-to-total thiol ratios (P = .027) were significantly higher in lung transplant recipients. Native thiol-to-total thiol ratios were lower in lung transplant recipients (P = .027). When we examined patients according to transplant indication, no statistically significant differences were found in dynamic thiol-disulfide homeostasis parameters, except for total thiol and disulfide levels. We also found no significant differences when we examined dynamic thiol-disulfide homeostasis parameters according to time after transplant.

CONCLUSIONS

Thiol-related antioxidant activity is significantly reduced after lung transplant, regardless of indication and transplant time. Ensuring oxidative balance in lung transplant recipients with an antioxidant supplement regimen can prevent damage from oxidative stress.

Biomarkers of Oxidative Stress in Systemic Lupus Erythematosus Patients with Active Nephritis

Oxidative stress plays an important role in systemic lupus erythematosus (SLE) and especially in lupus nephritis (LN). The aim of this study was to compare redox-related biomarkers between patients with active LN, quiescent SLE (Q-SLE) and healthy controls (HC) and to explore their association with clinical characteristics such as disease activity in patients. We investigated levels of plasma free thiols (R-SH, sulfhydryl groups), levels of soluble receptor for advanced glycation end products (sRAGE) and levels of malondialdehyde (MDA) in SLE patients with active LN (n = 23), patients with quiescent SLE (n = 47) and HC (n = 23). Data of LN patients who previously participated in Dutch lupus nephritis studies and longitudinal samples up to 36 months were analyzed. Thiol levels were lower in active LN at baseline and Q-SLE patients compared to HC. In generalized estimating equation (GEE) modelling, free thiol levels were negatively correlated with the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) over time (p < 0.001). sRAGE and MDA were positively correlated with the SLEDAI over time (p = 0.035 and p = 0.016, respectively). These results indicate that oxidative stress levels in LN patients are increased compared to HC and associated with SLE disease activity. Therefore, interventional therapy to restore redox homeostasis may be useful as an adjunctive therapy in the treatment of oxidative damage in SLE.

Oxidant-antioxidant balance in girls with precocious puberty: a case-control study

This case-control study aims to evaluate the oxidant-antioxidant balance in girls having central precocious puberty (CPP) and premature thelarche (PT). Thirty-four girls having CPP, 24 girls having PT, and 49 healthy growing girls between 7 and 9 years of age admitted to child health supervision were enrolled. Total antioxidant and oxidant capacity, myeloperoxidase, catalase, superoxide dismutase, total thiol, native thiol, and disulfide levels were analyzed in serum samples. Low total oxidant status (<12.0) was found to be highest in the CPP group, lowest in the control group, and the PT group was in between them. After controlling bone age and z score for body mass index, generalized linear models revealed lower oxidative stress index values in the CPP and the PT groups than the control group. Other studied parameters did not differ among groups. Precocious puberty in girls is associated with some changes in the oxidant-antioxidant status.

Maternal Epilepsy and Umbilical Cord Blood Oxidative Stress Level

INTRODUCTION

We investigated the effect of epilepsy on cord blood oxidative stress status.

MATERIAL AND METHODS

Thirty (n = 30) pregnant women with epilepsy and thirty (n = 30) healthy controls enrolled in this case control study. Albumin and IMA values and dynamic thiol/disulfide parameters were measured.

RESULTS

Decreased native thiol and total thiol levels were found in the epilepsy group when compared to the control group (p: 0.001, p: 0.002). Higher IMA (p: 0.036) and lower albumin cord levels (P < 0.001) were measured in the epilepsy group with respect to the control group. Apgar scores at 1 and 5 miutes were lower in the epilepsy group (respectively; p = 0.012, p = 0.010). A negative correlation was found between IMA and cord pH value (r = 0.288 p = 0.034).

CONCLUSION

This study showed that epilepsy may alter thiol disulfide homeostasis and IMA levels.

Thiol-Disulfide Homeostasis in Neonatal Patients with Urinary Tract Infection

OBJECTIVE

Urinary tract infection (UTI) is a disease that can cause significant complications in the neonatal period. The thiol-disulfide homeostasis is one of the important antioxidant defense mechanisms. The purpose of this study is to show the relationship between UTI and thiol-disulfide homeostasis in newborns.

STUDY DESIGN

In this prospective study, 40 newborns with UTI and 40 healthy controls were included. Thiol-disulfide tests (disulfide, native thiol, and total thiol levels) and septic screening tests were performed before and after antibiotherapy in UTI group. The control group was selected from healthy newborns who applied to the outpatient clinic.

RESULTS

The C-reactive protein and interleukin-6 levels were higher, while native thiol and native thiol/total thiol ratio were significantly lower in pretreatment group compared with posttreatment and control group. Also, the levels of disulfide, ischemia modified albumin, disulfide/native thiol ratio, and disulfide/total thiol ratio were higher in pretreatment group compared with posttreatment group.

CONCLUSION

The thiol-disulfide homeostasis is an important indicator of oxidative stress during infections. It is valuable to be detected with small amounts of serum in newborns. These molecules can be used to support the diagnosis of UTI in the newborn. Further studies are needed to define the role of thiol-disulfide homeostasis in the UTI of newborn.

KEY POINTS

· The thiol-disulfide homeostasis can be an important indicator of oxidative stress during infections such as UTI.. · The thiol-disulfide homeostasis of newborn is valuable to be detected with small amounts of serum in neonatal period.. · Laboratory tests such as white blood cell count, erythrocyte sedimentation rate, and C-reactive protein are not significantly different in UTIs..

Evaluation of thiol/disulfide hemostasis and serum Ischemia modified albumin as oxidative stress biomarkers in systemic lupus erythematosus patients: Relationship with major organ involvement and disease activity

OBJECTIVES

We aimed to compare thiol/disulfide hemostasis and serum ischemia-modified albumin (IMA) levels, which are indicators of oxidative stress (OS), in patients with systemic lupus erythematosus (SLE), with the healthy control (HC) group and to evaluate the relationship of these parameters with disease activity and major organ involvement.

MATERIAL-METHODS

Eighty-four SLE patients and 96 HCs were included in this study. The disease activity of SLE patients was calculated using The Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K). Patients with SLEDAI-2K ≤ 5 were classified as low disease activity (LDA) and those with SLEDAI-2K > 6 as high disease activity (HDA). Thiol/disulfide hemostasis was evaluated using a new automated method and natural thiol (NT), total thiol (TT), disulfide (SS) levels, SS/NT, SS/TT, NT/TT ratios, and serum IMA levels were recorded.

RESULTS

NT and TT levels were significantly lower (490.11 ± 123.61 vs 536.96 ± 86.05, p = 0.003) (532.56 ± 125.80 vs 565.72 ± 89.82, p = 0.046), SS level (21.22 ± 11.75 vs 13.37 ± 9.31, p < 0.001) was higher, and SS/TT (4.64 ± 2.93 vs 2.52 ± 1.82, p < 0.001) and SS/NT (4.12 ± 2.33 vs 2.35 ± 1.59, p < 0.001) ratios were significantly higher in SLE patients compared to HCs. IMA values were not different between the two groups (p = 0.920). NT (449.84 ± 136.98 vs 520.32 ± 104.11, p = 0.012) and TT levels (492.01 ± 138.45±562.97 ± 107.09, p = 0.013) were significantly lower and serum IMA levels (0.802 ± 0.089 vs 0.764 ± 0.040, p = 0.023) were significantly higher in SLE patients with HDA than in LDA patients. There was a weak negative correlation between NT (r = -0.284, p=0.009) (r = -0.291, p = 0.007) and TT levels (r = -0.281, p = 0.010) (r = -0.289, p = 0.008) and a weak positive correlation between IMA levels (r = 0.279, p = 0.011) (r = 0.263, p = 0.016) and SLEDAI-2K, and major organ involvement.

CONCLUSION

It is thought that thiol/disulfide hemostasis and IMA levels may be used as ideal biomarkers of OS in SLE patients and may reflect the disease activity and major organ involvement.

Hydrogen Sulfide Regulates Irisin and Glucose Metabolism in Myotubes and Muscle of HFD-Fed Diabetic Mice

Irisin, a novel myokine, is secreted by the muscle following proteolytic cleavage of fibronectin type III domain containing 5 (FNDC5) and is considered a novel regulator of glucose homeostasis. Cystathionine γ-lyase (CSE) produces hydrogen sulfide (H₂S) and is involved in glucose homeostasis. We examined the hypothesis that H₂S deficiency leads to decreased FNDC5 and irisin secretion, and thereby alters glucose metabolism. High-fat diet-fed mice exhibited elevated blood glucose and significantly reduced levels of CSE, H₂S, and PGC-1α, with decreased FNDC5/irisin levels and increased oxidative stress in the muscle compared with those of normal diet-fed mice (control). High glucose or palmitate decreases CSE/PGC-1α/FNDC5 levels and glucose uptake in myotubes. Inhibitors (propargylglycine and aminooxyacetate) of H₂S producing enzymes or CSE siRNA significantly decreased levels of H₂S and FNDC5 along with PGC-1α; similar H₂S-deficient conditions also resulted in decreased GLUT4 and glucose uptake. The levels of H₂S, PGC-1α, and FNDC5 and glucose uptake were significantly upregulated after treatment with l-cysteine or an H₂S donor. Myoblast differentiation showed upregulation of PGC-1α and FNDC5, which was consistent with the increased expression of CSE/H₂S. These findings suggest that the upregulation of H₂S levels can have beneficial effects on glucose homeostasis via activation of the PGC-1α/FNDC5/irisin signaling pathway.

The Evaluation of Thiol/Disulfide Homeostasis and Oxidative DNA Damage in Patients with Obsessive Compulsive Disorder

Objective

In this study, we aimed to examine thiol/disulfide homeostasis and oxidative DNA damage in patients with OCD and compare them with healthy controls.

Methods

Thirty-five patients previously diagnosed with OCD in Van Yuzuncu Yil University Department of Psychiatry and thirty-three healthy volunteers were included in the study. The severity of the symptoms was measured using the Yale-Brown Obsessive-Compulsive Scale. Five μL of blood samples were taken from the patient and control groups. The samples were stored at appropriate conditions until use. Leukocyte DNA was isolated and the levels of 8-hydroxy-2-deoxyguanosine (8-OHdG) and deoxyguanosine were detected to assess the oxidative DNA damage. The level of oxidative DNA damage was expressed as 8-OHdG/10⁶dG. Total thiol/native thiol levels were measured for thiol/disulfide homeostasis. The level of disulfide was determined by subtracting the native thiol value from the total thiol value and the result was divided by two. Results were given as percentages.

Results

The total and native thiol levels in patients with OCD were significantly lower, and the disulfide levels were significantly higher in patients with OCD than healthy control subjects. In addition, 8-OHdG, an indicator of DNA damage, was significantly lower in the control group compared to the patient group.

Conclusion

Increased levels of disulfide/native thiol and disulfide/total thiol in patients with OCD show that levels of oxidative stress were elevated and therefore, higher 8-OHdG levels in patients with OCD is a marker of oxidative DNA damage.

Fructose and methylglyoxal-induced glycation alters structural and functional properties of salivary proteins, albumin and lysozyme

Glycation process refers to reactions between reduction sugars and amino acids that can lead to formation of advanced glycation end products (AGEs) which are related to changes in chemical and functional properties of biological structures that accumulate during aging and diseases. The aim of this study was to perform and analyze in vitro glycation by fructose and methylglyoxal (MGO) using salivary fluid, albumin, lysozyme, and salivary α-amylase (sAA). Glycation effect was analyzed by biochemical and spectroscopic methods. The results were obtained by fluorescence analysis, infrared spectroscopy (total attenuated reflection-Fourier transform, ATR-FTIR) followed by multivariate analysis of principal components (PCA), protein profile, immunodetection, enzymatic activity and oxidative damage to proteins. Fluorescence increased in all glycated samples, except in saliva with fructose. The ATR-FTIR spectra and PCA analysis showed structural changes related to the vibrational mode of glycation of albumin, lysozyme, and salivary proteins. Glycation increased the relative molecular mass (Mr) in protein profile of albumin and lysozyme. Saliva showed a decrease in band intensity when glycated. The analysis of sAA immunoblotting indicated a relative reduction in intensity of its correspondent Mr after sAA glycation; and a decrease in its enzymatic activity was observed. Carbonylation levels increased in all glycated samples, except for saliva with fructose. Thiol content decreased only for glycated lysozyme and saliva with MGO. Therefore, glycation of salivary fluid and sAA may have the potential to identify products derived by glycation process. This opens perspectives for further studies on the use of saliva, an easy and non-invasive collection fluid, to monitor glycated proteins in the aging process and evolution of diseases.

Evaluation of Oxidative Stress Biomarkers, Pro-Inflammatory Cytokines, and Histological Changes in Experimental Hypertension, Dyslipidemia, and Type 1 Diabetes Mellitus

The present study aims to compare the oxidative stress biomarkers, pro-inflammatory cytokines, and histological changes induced by three cardiovascular risk factors, namely, hypertension, dyslipidemia, and type 1 diabetes mellitus. Hypertension was induced with 40 mg/kg body weight (b.w.) of N omega-nitro-L-arginine-methyl (L-NAME) administered orally. Dyslipidemia was induced by the administration of a diet with a high cholesterol (2%) content. Diabetes mellitus was induced by intraperitoneal administration of a single dose of streptozocin (65 mg/kg). Malondialdehyde (MDA) and total oxidative status (TOS) are increased by all three cardiovascular risk factors (up to 207%). The indirect assessment of NO synthesis (NOx) is observed to be reduced after L-NAME administration (43%), and dyslipidemia induction (16%), while type 1 diabetes mellitus is associated with the highest levels of NOx (increased 112%). Hypertension, dyslipidemia, and type 1 diabetes reduced the total antioxidative capacity (TAC) and total thiol (SH) levels (up to 57%). The values of evaluated pro-inflammatory cytokines, tumour necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β), assessed from the ascending aorta were elevated by all three cardiovascular risk factors, with the highest levels induced by type 1 diabetes mellitus (up to 259%). The histopathological examination of the ascending and descending aorta revealed reversible pro-atherogenic changes consisting of the accumulation of lipid droplets in the subendothelial connective tissue on rats with hypertension and dyslipidemia. Irreversible pro-atherogenic changes consisting of a reduction of the specific elasticity of the arteries were observed in rats with type 1 diabetes mellitus. Type 1 diabetes mellitus demonstrates an alteration of the oxidative stress parameters, the elevation of tissue levels of the pro-inflammatory cytokines and causing irreversible pro-atherogenic changes on the aortic wall.

Dynamic Thiol/Disulfide Homeostasis and Oxidative DNA Damage in Adult Attention Deficit Hyperactivity Disorder

Objective

Insufficient number of oxidative stress studies have been conducted in patients with adult attention deficit hyperactivity disorder (ADHD). The objective of the current study is to examine the thiol/disulfide homeostasis as well as oxidative DNA damage levels in adult ADHD patients and to compare them with the results of healthy control subjects.

Methods

The study was inclusive of forty-nine patients who were diagnosed with adult ADHD, as well as thirty-three healthy volunteers to be used as the control group. The diagnosis of the patients was conducted according to the DSM-5 diagnostic criteria. Blood were stored under appropriate laboratory conditions. For the purpose of detecting the oxidative DNA damage level, an extraction of genomic DNA from leukocytes was carried out, and furthermore the levels of 8-hydroxy-2-deoxyguanosine (8-OHdG), apart from deoxyguanosine, were measured accordingly.

Results

Total thiol and the native thiol levels were observed to be statistically lower in adult ADHD patients as compared to the subjects in the healthy control group (p = 0.001). It was observed that the disulfide levels were higher in adult ADHD patients as compared to the healthy control subjects (p = 0.001). In addition, the levels of 8-OHdG, which are considered as a marker for assessing DNA damage, were found to be significantly lower in the control group as compared to the adult ADHD patients (p = 0.001).

Conclusion

It was observed that the thiol/disulfide homeostasis had shifted towards disulfide, and 8-OHdG levels were increased in adult ADHD patients.

Thiol/disulfide homeostasis and its relationship with insulin resistance in patients with rosacea

BACKGROUND

Rosacea is a chronic inflammatory cutaneous disease that can be associated with cardiometabolic disorders. Oxidative stress is included in the pathogenesis of rosacea, and thiol-disulfide homeostasis (TDH) acts as antioxidants.

OBJECTIVE

To evaluate the TDH and metabolic parameters in patients with rosacea.

MATERIAL AND METHODS

A total of 42 rosacea patients and 50 controls participated in this prospective study. Demographic data, clinical entities, anthropometric measurements, and laboratory findings were recorded. Additionally, TDH was measured by an automated spectrophotometric method.

RESULTS

Rosacea patients had greater body mass index values (27.9 ± 5.2 kg/m² vs. 23 ± 1.4 kg/m², p < 0.001), waist-hip ratios (0.87 ± 0.1 vs. 0.77 ± 0.8, p < 0.001), and insulin resistance (3.0 ± 2.0 vs. 1.3 ± 0.5, p < 0.001) compared with controls. Disulfide levels, the disulfide/native thiol ratio (DNTR), and the disulfide/total thiol ratio (DTTR) were increased (p < 0.05) in rosacea patients. Native thiol and total thiol levels and the native/total thiol ratio (NTTR) were decreased in rosacea patients (p < 0.05). Different rosacea subtypes had no effect on oxidative stress markers. The duration of illness and insulin resistance values significantly correlated with DNTR and DTTR in the rosacea group (p < 0.05).

CONCLUSION

Rosacea has a metabolic milieu with increased oxidative stress and insulin resistance.

The association of dynamic thiol-disulphide balance with white-coat hypertension

OBJECTIVE

Dynamic thiol-disulphide homeostasis is an indicator of the antioxidant system that interacts early with the oxidative environment. This study aimed to assess the dynamic thiol/disulphide balance in individuals with white-coat hypertension (WCH).

METHODS

This cross-sectional study included a total of 117 individuals who presented to our outpatient cardiology clinic. Seventy patients were diagnosed with WCH. All blood samples were obtained from the patients after a minimum of 8 h of fasting, centrifuged immediately, stored in Eppendorf tubes, and protected at -80°C.

RESULTS

The two groups were well-balanced in terms of age, gender, and BMI. Native thiol and total thiol levels were lower in the WCH group than in normotensive individuals. However, disulphide levels were higher in the former. Serum disulphide concentration positively correlated with 24-h SBP, and 24-h DBP. In backward stepwise logistic regression analysis, serum disulphide [odds ratio (OR) = 1.165 (1.089-1.245), 95% confidence interval (CI), P < 0.001] and serum total thiol levels [OR = 0.992 (0.984-1.000), 95% CI, P = 0.050] were independently associated with WCH.

CONCLUSION

We demonstrated that dynamic thiol/disulphide balance shifted strongly towards disulphide formation due to thiol oxidation in patients with WCH.

The role of oxidative stress in onychomycosis: Thiol/disulphide homeostasis

OBJECTIVES

Onychomycosis is the general term to define fungal nail infections that arise from dermatophytes, non-dermatophytic moulds and yeasts. Thiol/disulphide homeostasis is a new indicator of oxidative stress. In this study, we aimed to investigate the role of thiol/disulphide balance in the pathogenesis of onychomycosis.

METHODS

This cross-sectional study included adult patients with onychomycosis who were admitted to the dermatology department and healthy adult volunteers without any dermatologic or systemic condition. The patients and controls were evaluated in terms of native thiol, total thiol, and disulphide levels, and disulphide/native thiol, disulphide/total thiol and native thiol/total thiol ratios. The possible association between these parameters and clinical subtypes of onychomycosis and demographic characteristics was also investigated.

RESULTS

A total of 52 patients with onychomycosis and 50 healthy subjects were enrolled in the study. The patient group showed lower levels of total thiol, native thiol and native thiol/total thiol ratio, and higher ratios of disulphide/native thiol and disulphide/total thiol. No statistically significant relationship was found between the parameters, clinical subtypes of onychomycosis and demographic characteristics (p > .05).

CONCLUSION

Patients with onychomycosis showed a shifted thiol/disulphide homeostasis towards oxidative stress with a reduction in thiols and an increase in disulphide/native thiol, and disulphide/total thiol ratios. These findings may indicate the role of oxidative stress in the pathogenesis of onychomycosis.

Simultaneous Determination of Chiral Thiol Compounds and Monitoring of Dynamic Changes in Human Urine after Drinking Chinese Korean Ethnic Rice Wine

Chinese Korean ethnic rice wine, a traditional fermented wine made from rice or corn, has antioxidant and antihypertensive activities. Although the determination of amino acids and other nutrients in rice wine has been reported, the existence of chiral thiol compounds has not been published in the literature. Therefore, we established a highly sensitive and selective ultrahigh-performance liquid chromatography-high-resolution mass spectrometry method for simultaneous determination and chiral separation of dl-Cys-GSH, dl-Cys-Cys, and dl-Cys-Hcy based on (R)-(5-(3-isothiocyanatopyrrolidin-1-yl)-5-oxopentyl) triphenylphosphonium derivatization. Three thiol diastereomers were completely separated on a YMC Triart C18 (2.0 × 150 mm, 1.9 μm) column with a resolution value (Rs) ≥ 1.52. The correlation coefficients were ≥0.9996, limit of detection was 2.40-7.20 fmol, and mean recoveries were 83.33-98.59%. Furthermore, fitted curves for dynamic changes in three kinds of chiral thiols in 10 human urine samples after drinking rice wine were drawn. Meanwhile, the metabolic changes in d/l-thiol compounds in human urine were investigated.

Effect of ciprofloxacin vs levofloxacin on QTc-interval and dysglycemia in diabetic and non-diabetic patients

BACKGROUND

Levofloxacin and ciprofloxacin are more commonly used amongst fluoroquinolone class and the question of cardiac safety and glucose hemostasis of this class has been raised.

OBJECTIVE

To compare intravenous levofloxacin and ciprofloxacin regarding their risk on QTc prolongation and dysglycemia in diabetic and non-diabetic patients.

METHODS

A randomised prospective study at Beni-Suef university hospital was conducted on 200 adult patients over 6 months. The patients received intravenous levofloxacin 750mg once daily or ciprofloxacin 400mg twice daily. Electrocardiogram and fasting blood glucose were obtained from each patient before starting the antibiotic, 24 hours, 72 hours after the first dose, and 72 hours after antibiotics cessation.

RESULTS

The results of the current study showed the relative risk for QTc prolongation with levofloxacin was more than ciprofloxacin by about 4 and 1.5 times in diabetic and non-diabetic patients, respectively. The relative risk for dysglycemia with levofloxacin was 2.28 and 1.39 times more than ciprofloxacin in diabetic and non-diabetic patients, respectively.

CONCLUSION

The present study showed that the risk for QTc prolongation and hyperglycemia was greater with levofloxacin than ciprofloxacin in diabetic and non-diabetic patients. In addition, the risk for hypoglycemia was greater with levofloxacin than ciprofloxacin in non-diabetic patients.

Dynamic thiol/disulfide homeostasis as oxidative stress marker in diabetic ketoacidosis

Background/aim

The aim of present study was to investigate the dynamic thiol/disulfide homeostasis as oxidative stress marker in diabetic ketoacidosis (DKA).

Materials and methods

A total of 77 participants consisting of 32 patients with DKA and 45 healthy volunteers were included in the study. Thiol/disulfide homeostasis (TDH) [total thiol-native thiol/disulfide changes] were measured in both groups (patient group and control group) using a brand new method developed by Erel and Neselioglu. Half of the difference between total thiol and native thiol concentrations gives the amount of disulfide bond. 


Results

Total thiol, native thiol, and disulfide levels in blood were found to be low. The levels of total thiol (P < 0.001) and native thiol (P < 0.001 ) were significantly lower in patients with DKA than in the control group. At the same time, the level of disulfide was nonsignificantly lower in the patient group than the control group (P = 0.388). The level of IMA was higher in the patient group than in the control group (P < 0.001).

Conclusion

The total thiol, native thiol, and disulfide levels in DKA decrease in favor of oxidative stress.

Altered thiol/disulfide homeostasis and ischemia-modified albumin levels in children with irritable bowel syndrome

BACKGROUND

In this study, we assessed thiol/disulfide homeostasis (TDH) parameters and ischemia-modified albumin (IMA) levels in children with irritable bowel syndrome (IBS) compared with healthy children.

METHODS

Fifty-six children with IBS and 53 healthy children were included in the study after assessment of inclusion and exclusion criteria. Plasma thiol/disulfide and IMA levels were compared between children with and without IBS.

RESULTS

The mean values of native thiol, total thiol, and disulfide were 343.779 ± 138.654 μmol/L, 365.398 ± 140.148 μmol/L, and 23.190 ± 4.978 μmol/L, respectively, in the IBS group and 409.908 ± 69.288 μmol/L, 433.481 ± 76.891 μmol/L, and 20.090 ± 4.252 μmol/L, respectively, in the control group. Native thiol and total thiol values were significantly reduced in the IBS group compared with the control group. The mean IMA values were 0.835 ± 0.083 (g/L) and 0.778 ± 0.072 in the IBS and control groups, respectively. The IMA value was significantly increased in the IBS group.

CONCLUSION

Impaired thiol/disulfide homeostasis and increased IMA levels can be considered etiological factors in children with IBS.

The Relationship between Choroidal Thickness and Intracellular Oxidised-reduced Glutathione and Extracellular Thiol-disulfide Homeostasis at Different Stages of Diabetic Retinopathy

Purpose: To evaluate the relationship between diabetic retinopathy and oxidative damage by measuring intracellular and extracellular thiol levels, and to compare intracellular and extracellular thiol levels. Method: In this prospective, cross-sectional, and comparative study, 25 healthy control participants (group 1), a total of 25 diabetic macular edema (DME) patients with non-proliferative diabetic retinopathy (DRP) and without DME (group 2), and 25 DME patients with non-proliferative DRP and with DME (group 3) were included. Choroidal thickness (ChT) and central macular thickness (CMT) were measured by spectral domain optic coherence tomography. For the evaluation of antioxidant/oxidant balance, intracellular GSH (reduced glutathione) and GSSG (oxidized glutathione), extracellular SH (thiol) and SS (disulfide) levels were measured and recorded. Results: Comparing intracellular and extracellular thiol levels between groups, intracellular GSSG level and GSSG/GSH percent ratio, and extracellular disulfide and SS/SH percent ratio values were higher in diabetic patients than healthy participants. Choroidal thicknesses were significantly thinner in DRP groups compared to the healthy population. When the relationship between choroidal thicknesses and thiol levels was investigated, there were significant relationships between choroidal thicknesses and thiol levels in group 3. Conclusion: Oxidative stress and impaired intracellular GSH/GSSG and serum SH/SS balances were observed to have an effect on DRP and DME pathogenesis. In addition, in groups with and without DME, thinning in choroidal thicknesses and the relationship between these thicknesses and intra/extracellular oxidative stress indicators can also be explained.

Thiol-disulfide homeostasis: an integrated approach with biochemical and clinical aspects

Dynamic thiol-disulfide homeostasis (TDH) is a new area has begun to attract more scrutiny. Dynamic TDH is reversal of thiol oxidation in proteins and represents the status of thiols (-SH) and disulfides (-S-S-). Organic compounds containing the sulfhydryl group is called thiol, composed of sulfur and hydrogen atoms. Disulfides are the most important class of dynamic, redox responsive covalent bonds build in between two thiol groups. For many years, thiol levels were analyzed by several methods. During last years, measurements of disulfide levels have been analyzed by a novel automated method, developed by Erel and Neselioglu. In this method, addition to thiol (termed as native thiol) levels, disulfide levels were also measured and sum of native thiol and disulfide levels were termed as total thiol. Therefore, TDH was begun to be understood in organism. In healthy humans, TDH is maintained within a certain range. Dysregulated dynamic TDH has been implicated several disorders with unknown etiology. A growing body of evidence has demonstrated that the thiol-disulfide homeostasis is involved in variety diseases, such as diabetes mellitus, hypertension, nonsmall cell lung cancer, familial Mediterranean fever (FMF), inflammatory bowel diseases, occupational diseases, gestational diabetes mellitus and preeclampsia. These results may elucidate some pathogenic mechanism or may be a predictor indicating diagnostic clue, prognostic marker or therapeutic sign. In conclusion, protection of the thiol-disulfide homeostasis is of great importance for the human being. Evidence achieved so far has proposed that thiol-disulfide homeostasis is an important issue needs to elucidate wholly.

Evaluation of thiol/disulfide homeostasis in patients with gestational diabetes mellitus

This study aimed to study the dynamic thiol/disulfide homeostasis in pregnant women with gestational diabetes mellitus (GDM). Forty-five pregnant women with GDM and 45 age-matched healthy pregnancies were included in this study. Thiol/disulfide homeostasis was measured using a commercial kit (Rel Assay Diagnostics). The patients with GDM had significantly higher disulfide concentrations than healthy pregnant patients (p = .001). Besides, the GDM group had significantly higher disulfide/total thiol, disüplhide/native thiol, and native thiol/total thiol ratio than healthy pregnant patients (p = .001, p = .001 and p = .001, respectively). The significantly higher concentrations of disulfide, disulfide/total thiol, disüplhide/native thiol, and native thiol/total thiol ratio in women with GDM could be considered as the increased oxidative stress.

Ischemia-Modified Albumin Levels and Thiol-Disulphide Homeostasis in Diabetic Macular Edema in Patients with Diabetes Mellitus Type 2

PURPOSE

It was aimed to assess the role of thiol-disulphide homeostasis and ischemia-modified albumin (IMA) level in the development of diabetic macular edema (DME) in patients with diabetes mellitus type 2 (T2DM).

MATERIALS AND METHODS

Sixty-six study patients were divided into two groups. Group I included 43 patients with T2DM and DME, and Group 2 included 23 patients with T2DM without eye involvement. A novel colorimetric method was used to assess thiol-disulphide homeostasis. Between the two groups IMA, total anti-oxidant, and total oxidant levels were measured and compared.

RESULTS

In Group 1, total and native thiol levels and disulphide levels were lower compared to Group 2 (p = .025, p < .001 and p = .013, respectively). Disulphide/native thiol, disulphide/total thiol ratios and native thiol/total thiol were similar between the groups. Total anti-oxidant level (TAL) reduced whereas total oxidant level (TOL) increased in Group 1 compared to Group 2 (p = .001, p = .002, respectively). Albumin level decreased, whereas IMA level increased in Group 1 compared to Group 2 (p < .001 for both).

CONCLUSIONS

The disruption in thiol/disulphide homeostasis, increased IMA and oxidative stress have an impact on the development of diabetic macular edema.

Dynamic thiol/disulphide homeostasis metrics as a risk factor for peripheral arterial disease

OBJECTIVE

To examine dynamic thiol/disulphide homeostasis metrics as a novel risk factor of oxidative stress in patients with peripheral arterial disease.

METHODS

One hundred patients with lower extremity peripheral arterial disease (a study group) and 100 control subjects were included in this prospective case-control study. Participants' baseline clinical characteristics and laboratory data including some oxidant/antioxidant status parameters such as albumin, ferroxidase and myeloperoxidase, and thiol/disulphide homeostasis parameters such as native thiol, total thiol and disulphide, as well as native thiol/total thiol, disulphide/native thiol and disulphide/total thiol ratios were all recorded and then compared between the groups.

RESULTS

Mean albumin and ferroxidase, and median myeloperoxidase levels were found to be significantly higher in patients with the peripheral arterial disease than in control group (p = 0.045, p = 0.000 and p = 0.000, respectively). Mean native thiol and total thiol, and median disulphide levels were found to be significantly lower in the study group as compared with the control group (p = 0.000, p = 0.000 and p = 0.037, respectively). According to the results of logistic regression analysis, systolic blood pressure, ferroxidase and myeloperoxidase levels were detected to be the independent predictors of peripheral arterial disease.

CONCLUSION

Our report is the first one in the literature investigating dynamic thiol/disulphide homeostasis metrics as a novel risk factor of oxidative stress in peripheral arterial disease. Dynamic thiol/disulphide homeostasis metrics may be used as a valuable risk factor of oxidative stress in patients with the peripheral arterial disease since it is readily available, easily calculated and relatively cheap.

Oxidative Stress in Children with Cutaneous Mastocytosis

Background: Thiols and ischemia-modified albumin (IMA) are novel biomarkers for the evaluation of the oxidative stress (OS) that has been associated with the pathogenesis of various neoplastic and inflammatory diseases. The aim of this study was to find out the dynamic thiol-disulfide homeostasis and IMA levels in patients with cutaneous mastocytosis (CM) to demonstrate the presence of the OS. Methods: A total of 36 patients with CM and 27 age- and sex-matched healthy participants were included in this study. Serum thiols and IMA levels were measured and compared between the 2 groups. Results: Levels of native thiol, total thiol, disulfide, disulfide/native thiol, disulfide/total thiol, native thiol/total thiol, and IMA were similar in both patients with CM and the control group. No significant difference was found with regard to mediator-releasing symptoms, clinical types, and remission status between the OS markers (thiol/disulfide variables and IMA levels) of the patients (P > 0.05). Conclusions: To our knowledge, this study is the first study in the literature that investigated thiol-disulfide homeostasis and IMA levels in pediatric patients with CM. Our study indicated that OS plays no role in the course of the pediatric CM.

The Significance of Thiol/Disulfide Homeostasis and Ischemia-modified Albumin Levels in Assessing Oxidative Stress in Obese Children and Adolescents

Objective

There is an association between obesity and several inflammatory and oxidative markers in children. In this study, we analyzed thiol/disulfide homeostasis and serum ischemia-modified albumin (IMA) levels for the first time in order to clarify and determine the oxidant/antioxidant balance in metabolically healthy and unhealthy children.

Methods

This study included obese children and healthy volunteers between 4-18 years of age. The obese patients were divided into two groups: metabolically healthy obese (MHO) and metabolically unhealthy obese (MUO). Biochemical parameters including thiol/disulfide homeostasis, and IMA concentrations were analyzed.

Results

There were 301 recruits of whom 168 (55.8%) were females. The obese children numbered 196 (MHO n=58 and MUO n=138) and healthy controls numbered 105. No statistically significant difference could be found in ages and genders of the patients among all groups (p>0.05, for all). Native thiol (SH), total thiol (SH+SS), and native thiol/total thiol (SH/SH+SS) ratio were statistically significantly lower in the MUO group than the control group (p<0.001, p=0.005, and p=0.005; respectively). Disulfide (SS), disulfide/native thiol (SS/SH), disulfide/total thiol (SS/SH+SS) and IMA levels were statistically significantly higher in the MUO group than the control group (p=0.002, p<0.001, p<0.001, and p=0.001, respectively).

Conclusion

Chronic inflammation due to oxidative stress induced by impaired metabolic parameters in MUO children caused impairment in thiol redox homeostasis. Our data suggested that the degree of oxidant imbalance in obese children worsened as obesity and metabolic abnormalities increased. It is hypothesized that thiol/disulfide homeostasis and high serum IMA levels may be reliable indicators of oxidant-antioxidant status in MUO children.

Thiol/disulfide homeostasis and ischemia modified albumin levels in autoimmune gastritis and their relations with gastric emptying

Background/aim

Autoimmune gastritis is an autoimmune and inflammatory disorder. The aim of this study is to examine dynamic thiol/disulfide homeostasis and ischemia modified albumin levels, and to analyze the association between thiol/disulfide homeostasis and gastric emptying time in autoimmune gastritis.

Materials and methods

Thiol/disulfide homeostasis tests and ischemia modified albumin levels were determined in 50 autoimmune gastritis patients and 53 healthy subjects. Patients with delayed and normal gastric emptying were compared by thiol/disulfide homeostasis tests.

Results

The results showed that native thiol (μmol/L), total thiol (μmol/L), and native thiol/total thiol ratio (%) of the patients with autoimmune gastritis decreased compared to the control group (177.7 ± 34.18 vs. 245.25 ± 33.83, P = 0.001, 227.25 ± 36.78 vs. 284.20 ± 27.19, P = 0.03, and 8.84 ± 1.1 vs. 7.74% ± 1.3%, P = 0.001). In addition, native thiol (μmol/L), total thiol (μmol/L), and native thiol/ total thiol ratio (%) were found to be lower in patients with delayed gastric emptying (198.65 ± 24.27 vs. 167.12 ± 20.51, 241.81 ± 27.14 vs. 213.92 ± 26.35, 8.34 ± 1.29 vs. 7.20 ± 1.83, P = 0.001). Disulfide level, disulfide/native thiol, disulfide/total thiol (P = 0.001) ratios, and ischemia modified albumin levels (ABSU, 0.71 ± 0.08 vs. 0.83 ± 0.07) were found to be higher in autoimmune gastritis patients with delayed gastric emptying (P = 0.001).

Conclusion

The results showed that thiol/disulfide homeostasis in patients with autoimmune gastritis caused an increase in ischemia modified albumin and disulfide whereas a decrease in thiols. An altered thiol/disulfide balance was also observed in patients with delayed gastric emptying. These results suggest that the oxidative process is involved in patients with autoimmune gastritis.

Thiols as markers of redox status in type 1 diabetes mellitus

INTRODUCTION

Type 1 diabetes mellitus (T1DM) is associated with inflammation and the production of reactive oxygen species (ROS). Systemically, free thiols (R-SH) can be oxidized by ROS and circulating R-SH concentrations may directly reflect the systemic redox status. In this study the association between R-SH and clinical parameters of T1DM, including glycated haemoglobin A1c (HbA1c), was investigated. This is of particular interest since thiols are amendable to therapeutic intervention.

METHODS

As part of a prospective cohort study, data from 216 patients with a mean age of 45 (12) years, 57% male, diabetes duration 22 (16, 30) years and HbA1c of 60 (11) mmol/mol were examined. Baseline data were collected in 2002 and follow-up data in 2018. Cox proportional hazards regression analysis, with age, sex, HbA1c and R-SH, was used to assess prognostic factors for the development of complications.

RESULTS

At baseline, the plasma concentration of R-SH was 281.8 ± 34.0 μM. In addition to a lower concentration of NT-proBNP in the highest R-SH quartile (305-379 µM) there were no differences in baseline characteristics between the quartiles of R-SH. The Pearson correlation coefficient for R-SH and NT-proBNP was -0.290 (p < 0.001). No significant correlation between R-SH and baseline HbA1c (r = -0.024, p = 0.726) was present. During follow-up, 42 macrovascular and 92 microvascular complications occurred. In Cox regression, R-SH was not a prognostic factor for the development of microvascular [hazard ratio (HR) 0.999 (95% confidence interval (CI) 0.993, 1.005)] and macrovascular [HR 0.993 (95% CI 0.984, 1.002)] complications.

CONCLUSIONS

In addition to a negative association with NT-proBNP, no relevant relationships between R-SH and parameters of T1DM, including HbA1c, were present in this study.

Proatherogenic Importance of Carbamylation-induced Protein Damage and Type 2 Diabetes Mellitus: A Systematic Review

INTRODUCTION & BACKGROUND

Protein carbamylation is a non-enzymatic and irreversible posttranslational process. It affects functions of numerous enzymes, hormones and receptors playing several roles in diabetes pathogenesis by changing their native structures. Detrimental consequences of oxidative protein damage comprise, but are not limited to glyoxidation, lipoxidation and carbonylation reactions. Since the carbamylated plasma proteins are strongly related to the glycemic control parameters of diabetes, they may have an additive value and emerge as potential biomarkers for the follow up, prognosis and treatment of diabetes mellitus.

METHODS & RESULTS

To conduct our systematic review, we used PubMed and Semantic Scholar, and used 'Protein carbamylation and diabetes' and 'Protein carbamylation and atherosclerosis' as keywords and looked into about five hundred manuscripts. Manuscripts that are not in English were excluded as well as manuscripts that did not mention carbamylation to maintain the focus of the present article. Similar to glycation, carbamylation is able to alter functions of plasma proteins and their interactions with endothelial cells and has been shown to be involved in the development of atherosclerosis.

CONCLUSION

At this stage, it seems clear that protein carbamylation leads to worse clinical outcomes. To improve patient care, but maybe more importantly to improve healthcare-prevention, we believe the next stage involves understanding how exactly protein carbamylation leads to worse outcomes and when and in what group of people anti-carbamylation therapies must be employed.

The effect of newly initiated exercise training on dynamic thiol / disulphide homeostasis in sedentary obese adults

We studied dynamic thiol/disulphide homeostasis, an indicator of oxidative stress, to investigate the effects of newly initiated exercise training on sedentary obese adults. Seventeen sedentary obese adults and 15 normal-weight controls were included in the sample for this study. The obese adults were given a physical exercise training program that lasted twelve weeks. Before and after the exercise training program, blood samples were collected, and serum thiol/disulphide parameters were measured by using a novel technique. Before the start of the exercise training, it was observed that thiol/disulphide homeostasis was impaired, and this impairment was positively correlated with body mass index in sedentary obese adults because of the higher reactive oxygen species production in adipose tissue. However, while the obese participants' body mass index significantly decreased, the thiol/disulphide homeostasis parameters in the obese adults did not change over time as calculated at the baseline and compared to the calculation after the twelve weeks of exercise training. Despite a decrease in body mass index that occurred after the twelve weeks of exercise training, there was a lack of improvement in the obesity-induced impairment of thiol/disulphide homeostasis, which suggests that a newly initiated exercise training program may lead to oxidative stress.

Antioxidant and Anti-Inflammatory Effects of Curcumin Nanoparticles on Drug-Induced Acute Myocardial Infarction in Diabetic Rats

We have investigated the cardio-protective effects of pretreatment with curcumin nanoparticles (CUN) compared to conventional curcumin (CUS) on the changes in oxidative stress parameters and inflammatory cytokine levels during induced acute myocardial infarction (AMI) in rats with diabetes mellitus (DM). DM was induced with streptozotocin, and AMI with isoproterenol. Eight groups of seven Wister Bratislava rats were included in the study. The N-C was the normal control group, AMI-C was the group with AMI, DM-C was the group with DM, and DM-AMI-C was the group with DM and AMI. All four groups received saline solution orally during the whole experiment. S-DM-CUS-AMI and S-DM-CUN-AMI groups received saline for seven days prior to DM induction and continued with CUS (200 mg/kg bw, bw = body weight) for S-DM-CUS-AMI and CUN for S-DM-CUN-AMI (200 mg/kg bw) for 15 days before AMI induction. The CUS-DM-CUS-AMI group received CUS (200 mg/kg bw), while the CUN-DM-CUN-AMI received CUN (200 mg/kg bw) for seven days prior to DM induction, and both groups continued with administration in the same doses for 15 days before AMI induction. CUS and CUN prevented elevation of creatine kinase, creatine kinase-MB, lactate dehydrogenase in all groups, with better results in the CUN (S-DM-CUN-AMI and CUN-DM-CUN-AMI groups). CUS and CUN significantly reduced serum levels of oxidative stress markers (malondialdehyde, the indirect assessment of nitric oxide synthesis, and total oxidative status) and enhanced antioxidative markers (total antioxidative capacity and thiols, up to 2.5 times). All groups that received CUS or CUN showed significantly lower serum levels of tumor necrosis factor-alpha, interleukin-6, and interleukin-1β. The best antioxidative and anti-inflammatory effects were obtained for the group that received CUN before DM induction (CUN-DM-CUN-AMI group). Pretreatment with CUN proved higher cardio-protective effects exerting an important antioxidative and anti-inflammatory impact in the case of AMI in DM.

Different routes of insulin administration do not influence serum free thiols in type 1 diabetes mellitus

AIMS

Intraperitoneal (IP) insulin administration is a last-resort treatment option for selected patients with type 1 diabetes mellitus (T1DM). As the IP route of insulin administration mimics the physiology more closely than the subcutaneous (SC) route, we hypothesized that IP insulin would result in less oxidative stress (expressed as systemic level of free sulphydryl (R-SH) content) compared to SC insulin in subjects with T1DM.

MATERIALS AND METHODS

Prospective, observational case-control study. Serum thiol measurements were performed at baseline and at 26 weeks in age- and gender-matched patients with T1DM. Serum-free thiols, compounds with a R-SH group that are readily oxidized by reactive oxygen species, are considered to be a marker of systemic redox status.

RESULTS

A total of 176 patients, 39 of which used IP and 141 SC insulin therapy were analysed. Mean baseline R-SH concentration was 248 (31) μmol/L. In multivariable analysis, the route of insulin therapy had no impact on baseline R-SH levels. The estimated geometric mean concentrations of R-SH did not differ significantly between both groups: 264 (95% CI 257, 270) for the IP group and 258 (95% CI 254, 261) for the SC group with a difference of 6 (95% CI -2, 14) μmol/L.

CONCLUSIONS

Based on R-SH as a marker of systemic oxidative stress, these findings demonstrate that the route of insulin administration, IP or SC, does not influence systemic redox status in patients with T1DM.

The role of thiol-disulfide homeostasis in neonatal sepsis

BACKGROUND AND AIM

The thiol-disulfide homeostasis is essential for the body to maintain effective antioxidant defense mechanisms. We aimed to show the relationship between sepsis and thiol-disulfide homeostasis in newborns.

MATERIALS AND METHODS

In this prospective study, 66 newborns with sepsis (group 1) and 51 healthy controls (group 2) were included. In group 1, 53 newborns were diagnosed as clinical sepsis (group 1a) and 13 as definite sepsis (group 1b). The study has two time points; the day of diagnosis (step 1) and three days after the treatment (step 2). At step 1, group 1 and group 2 were compared for thiol-disulfide homeostasis as well as inflammatory markers. At step 2, the same laboratory tests were repeated only in group 1.

RESULTS

At step 1, the levels of C-reactive protein (CRP) and interleukin-6 (IL-6) were higher, while native thiol and total thiol levels were lower in group 1 compared to controls. Serum disulfide/total thiol ratio was also significantly higher in group 1. When analyzed for subgroups of group 1, demonstration of microorganism did not affect the serum thiol levels. Within group 1, at step 2, although CRP and IL-6 levels were significantly lowered compared to step 1, we did not observe significant changes in thiol-disulfide parameters.

CONCLUSIONS

The thiol-disulfide homeostasis may have a role in the pathogenesis of sepsis in newborns. The related parameters might be new markers for the diagnosis of sepsis in newborn patients. Further studies are needed to define the role of thiol-disulfide homeostasis in the course of neonatal sepsis.

Dynamic thiol/disulphide homeostasis in children with Duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) is a disorder that alter the expression of the dystrophin protein. Dystrophin deficiency alters the structural integrity of the contractile apparatus/sarcolemmal integrity, leading to dystrophic changes. Dystrophin deficiency results in an increase in oxidative stress. We aimed to investigate the thiol/disulfide balance as an oxidative stress marker in children with DMD. We included 24 DMD, and 22 healthy control group subjects in the study. The total thiol, native thiol, and disulphide levels were measured and the disulphide/native thiol, disulphide/total thiol and native thiol/total thiol ratios were calculated in DMD patients and healthy subjects. The mean age distribution of the patients and the healthy control group subjects was similar. The total thiol, native thiol, and disulfide levels were lower in DMD group than the healthy controls. In conclusion, the markers and ratios were measured and calculated in the blood, and we detected that the total thiol, and native thiol levels were lower in DMD group than the healthy controls. These results indicate that dynamic thiol-disulphide homeostasis can be used as a marker of oxidative stress in clinical trials with DMD.

Dynamic thiol/disulfide homeostasis as a novel indicator of oxidative stress in patients with urolithiasis

Purpose

A dynamic thiol/disulfide balance is pivotal in organizing anti-oxidant defense, detoxification, apoptosis, and enzyme activities, as well as transcription and cellular signal-transfer mechanisms. The connection between urolithiasis and oxidant/antioxidant status, which can be assessed through thiol-disulfide homeostasis (TDH), has not yet been examined. In this study, we evaluated the effects of TDH on the formation, size, and location of stones by examining the associations between TDH parameters and urolithiasis.

Materials and Methods

Patients with urolithiasis and healthy controls were recruited. The patients were divided into subgroups in terms of stone size (>15 mm or ≤15 mm) and stone location (nephrolithiasis or ureterolithiasis). TDH parameters were measured using a novel automatic and spectrophotometric method and compared statistically.

Results

TDH parameters were different between the urolithiasis and control groups. TDH tended towards the disulfide side in the urolithiasis group. Stone size increased an average 0.14 mm with a 1 µmol/L increase in disulfide level and decreased an average 0.058 mm with a 1 µmol/L increase in native thiol level. Disulfide and native thiol levels were found to be different across patients with stone size >15 mm, ≤15 mm, and controls (p<0.001 and p<0.001, respectively). However, the nephrolithiasis and ureterolithiasis groups were similar in respect of TDH parameters.

Conclusions

In this study, it was found that patients with urolithiasis displayed oxidative stress characterized by a TDH tendency towards the disulfide side, and an inadequate antioxidant response identified by a lower level of native thiol as compared with healthy controls.

Crohn's Disease in Clinical Remission Is Marked by Systemic Oxidative Stress

Introduction: Crohn’s disease (CD) is characterized by chronic and relapsing inflammation of the gastro-intestinal tract. It is assumed that oxidative stress contributes to CD pathogenesis, but systemic biomarkers for oxidative stress in CD are not yet identified. A reduction in free thiol groups in plasma proteins (“plasma free thiols”) reflects systemic oxidative stress since they are prime substrates for reactive oxygen species. Here, we determined the concentrations of plasma free thiols in CD patients and healthy controls and studied the putative correlation with disease parameters.

Methods: Free thiols were quantified in plasma of patients with CD in clinical remission [according to the Harvey Bradshaw Index (HBI)] and healthy controls and adjusted for plasma albumin. Albumin-adjusted free thiol concentrations were analyzed for associations with clinical and biochemical disease markers.

Results: Mean plasma free thiol concentrations were significantly lower in patients with CD (n = 51) compared to healthy controls (n = 27) (14.7 ± 2.4 vs. 17.9 ± 1.8 μmol/g albumin; P < 0.001). Patients with CD with above-average free thiols had significantly lower CRP levels (median 1.4 [interquartile range] [0.4; 2.6] vs. 3.6 [0.6; 7.0] mg/L; P < 0.05) and BMI (23.6 ± 4.8 vs. 27.1 ± 5.2 kg/m²; P < 0.05). Patients with CD having solely colonic disease demonstrated markedly reduced plasma free thiol concentrations compared to patients with ileocolonic involvement (13.2 ± 1.8 vs. 15.2 ± 2.2 μmol/g; P < 0.05). Finally, plasma free thiol concentrations negatively correlated with biomarkers of inflammation, including hsCRP, SAA, IL-17A (all P < 0.05), and VEGF.

Conclusion: Plasma free thiols are reduced in patients with CD in clinical remission compared to healthy controls. Thus, subclinical CD disease activity is reflected by systemic oxidative stress and plasma free thiols may be a relevant therapeutic target and biomarker to monitor disease activity in CD.

How does thiol/disulfide homeostasis change in children with type 1 diabetes mellitus?

AIMS

An increase in reactive oxygen species leads to formation of covalent bonds between sulfur atoms, thus thiol/disulfide homeostasis shifts towards the disulfide direction and oxidative damage occurs. We aimed to determine thiol/disulfide homeostasis in children with T1DM.

METHODS

Thiol/disulfide homeostasis was evaluated in 30 patients with T1DM and 30 age, gender matched healthy controls. Thiol/disulfide homeostasis parameters were measured using a novel automated measurement method and correlation between demographic data and parameters was measured.

RESULTS

There weren't any significant differences in age or gender between the T1DM and control groups. T1DM group, findings were as follows: native thiol: 388.3 ± 76.7 µmol/L, total thiol: 426.2 ± 87 µmol/L, disulfide: 18.9 ± 7 µmol/L, control group findings were as follows: native thiol: 423.1 ± 45.2 µmol/L, total thiol: 455.7 ± 49.9 µmol/L, disulfide: 16.2 ± 5.6 µmol/L. The disulfide/native thiol and disulfide/total thiol ratios were significantly higher in the T1DM group (p = 0.005 and p = 0.004, respectively), whereas the native thiol level and the native thiol/total thiol ratio were significantly lower in the T1DM group than in the control group (p = 0.036 and p = 0.015, respectively). There wasn't significant correlation between demographic data and thiol/disulfide homeostasis parameters.

DISCUSSION

This study shows that dynamic thiol/disulfide homeostasis in children with T1DM shifts towards the disulfide direction. We think that this shift is caused by oxidative damage in β-cells. Additional research on thiol/disulfide homeostasis in children with T1DM might provide techniques for early detection of oxidative damage in β-cells.

Thiol/Disulfide homeostasis in patients with rheumatoid arthritis

BACKGROUND

Oxidative stress may play an important role in rheumatoid arthritis (RA) etiopathogenesis. The thiol group is a very strong antioxidant. In this study, we aimed to investigate the presence of oxidative stress in patients with RA by evaluating thiol/disulfide homeostasis.

MATERIAL AND METHODS

A total of 50 female RA patients and 50 healthy female controls were included in this study. Thiol and disulfide values were calculated utilizing novel methods.

RESULTS

Native thiol (p < 0.001) and total thiol (p < 0.001) levels of RA patients were significantly lower compared to values in the control group. However, the disulfide (p < 0.001) levels of RA patients were strongly higher than in healthy individuals. A negative correlation was found between thiol and disease activity score-28 among the patients, whereas a positive correlation was found between disulfide and disease activity score-28 among the patients.

CONCLUSION

We found that the thiol-disulfide rate deteriorated in RA patients, with the proportion of disulfide increasing. There is a strong correlation between the decrease in thiol levels, increase in disulfide levels and the disease activity scores.

Is otitis media with effusion associated with oxidative stress? Evaluation of thiol/disulfide homeostasis

BACKGROUND

We evaluated the relationship between otitis media with effusion and thiol/disulfide homeostasis using a novel marker of oxidative stress.

METHODS

The study group consisted of 30 patients (mean age 8.33 ± 3.30 years) with bilateral otitis media with effusion admitted to our hospital. The control group consisted of 35 (mean age 7.40 ± 3.97 years) age-, sex-, and body mass index-matched healthy subjects. Thiol/disulfide homeostasis was measured using a newly developed method.

RESULTS

Native and total thiol levels were lower in the study than the control group (native thiols 421.37 ± 72 μmol/L vs. 464.46 ± 46.42 μmol/L, p < 0.05; total thiols 468.42 ± 77.89 μmol/L vs. 501.32 ± 50.30 μmol/L, respectively). Disulfide levels and the disulfide/native thiol and disulfide/total thiol ratios were higher in the study group (disulfides 23.56 ± 4.68 μmol/L vs. 18.43 ± 4.94 μmol/L; disulfide/native thiol ratio 5.65 ± 1.05 vs. 3.97 ± 1.03%; disulfide/total thiol ratio 5.06 ± 0.83 vs. 3.66 ± 0.88%, respectively).

CONCLUSION

Oxidative stress may be the major cause of the increase in oxidized thiols in patients with bilateral otitis media with effusion, however, this relationship requires further investigation.

The evaluation of thiol/disulphide homeostasis in diabetic nephropathy

AIMS

Thiol/disulphide homeostasis plays a critical role in antioxidant defense, and detoxification in body. Although alteration of thiol/disulfide homeostasis had been shown in patients with diabetes, the thiol/disulfide balance in patients with type 2 diabetes and nephropathy is not yet known.

METHODS

Twenty-six healthy volunteers (group 1), and 17 normal albuminuric (group 2), 24 middle albuminuric (group 3), 20 severe proteinuric (group 4) patients with type 2 diabetes were included. Proteinuria was tested by measuring microalbumin/creatinine ratio in spot urine. Thiol/disulphide homeostasis concentrations were measured using method developed by Erel et al. RESULTS: Mean blood urea and creatinine levels were found to be significantly higher and GFR level was found to be significantly lower in group 4 than in the other groups. Native thiol levels are significantly lower in groups with diabetes than in healthy group and in groups 3 and 4, compared to group 2. Total thiol level was significantly lower in groups 3 and 4 than group 1 and 2. Disulphide/native thiol and disulfide/total thiol ratios were significantly higher in the groups with diabetes than in group 1 and in the group 4 than in the group 2.

CONCLUSION

The level of native and total thiols were found to be decreased significantly with the grade of nephropathy in patients with type 2 diabetes and the balance had been disrupted in favor of disulphide. We suggest that deteriorated thiol/disulphide balance may be one of the important factors in the development or progression of diabetes induced nephropathy.

A new oxidative stress indicator: Effect of 5-hydroxytryptophan on thiol-disulfide homeostasis in exercise

OBJECTIVES

The aim of the present study was to evaluate the relationship between exercise and both 5-hydroxytryptophan and oxidative stress using thiol-disulfide homeostasis via what is likely a novel biomarker.

METHODS

Male albino Wistar rats (n = 32) were randomly divided into four groups as follows: control, exercise group, 5-hydroxytryptophan group (5H), and 5-HTP + exercise group (5Hex). Exercise and 5-HTP administration (25mg/kg per d) were performed 5d/wk for 10 wk. After completion of the experimental protocol, to determine oxidative stress parameters, serum total thiol and native thiol concentrations were measured. Dynamic disulfide status, reduced thiol, oxidized thiol (OT), and thiol oxidation reduction percentage ratios were compared between the groups. The methods used in the present study to measure dynamic thiol-disulfide homeostasis as calorimetric and duplex quantities were developed in 2014. These new methods are simple, reliable, and sensitive, with both high linearity and repeatability.

RESULTS

Compared with the control group, serum dynamic disulfide levels were significantly lower in the 5H group and highest in the control group. The lowest OT and the highest reduced thiol rates were determined to be in the 5H group. The highest OT value was found in the 5Hex group. Thiol oxidation reduction values were found to be highest in the 5H group and lowest in the 5Hex group.

CONCLUSIONS

Both 5-HTP and moderate exercise seem to be significantly effective in inhibiting oxidative damage. In addition, the new oxidative stress measurement method used in this study is a promising practical and useful method to evaluate and improve the performance of athletes.

Thiol/disulfide homeostasis as a marker of oxidative stress in rosacea: a controlled spectrophotometric study

BACKGROUND

Rosacea is the chronic inflammatory disease of the facial skin. Although its aetiology is not clear yet, inflammatory processes triggered by oxidative stress and oxidation of lipids have been suggested to play a role. While studies on the relationship between inflammation and oxidative stress are ongoing, thiol metabolism and its role in oxidative stress have also begun to be investigated. Thiols are among the key molecules of protein metabolism in the organism and they are the firstly consumed antioxidants in case of oxidative stress. Thiols regulate intracellular redox metabolism and protect keratinocytes against the results of oxidative alterations in the stratum corneum. There is a balance known as dynamic thiol/disulfide homeostasis between thiols and their oxidized forms; disulfides.

AIM

This study aimed to determine the effects of oxidative stress on protein metabolism in rosacea patients by investigating thiol/disulfide homeostasis using a newly developed and fully automated method. Determination of plasma thiol levels provides important clues regarding the extent of free radical-mediated oxidation of proteins causing damage in rosacea.

METHODS

The study included 50 rosacea patients who were diagnosed clinically or histopathologically with rosacea and 42 age- and gender-matched healthy controls. Plasma levels of native thiol, total thiol, and disulfide were determined. The following ratios were calculated: disulfide/native thiol ratio, disulfide/total thiol ratio, and native thiol/total thiol ratio.

RESULTS

The mean age was 41.8 ± 10.5 in the rosacea patients (35 females) and 42.5 ± 10.3 years in the control group (33 females). The mean disulfide level was found to be significantly higher in the rosacea patients than in the control group (23.4 ± 5.5 µM/L and 17.3 ± 6.2µM/L, respectively; p < 0.001). The mean disulfide/native thiol ratio (0.055 ± 0.016 vs. 0.041 ± 0.017) and the mean disulfide/total thiol ratio (0.049 ± 0.012 vs.0.037 ± 0.013) were significantly higher and the mean native thiol/total thiol ratio (0.884 ± 0.118 vs. 0.923 ± 0.027) was significantly lower in the patients as compared with the controls (p < 0.05 for all).

CONCLUSION

In rosacea patients, the thiol/disulfide balance was observed to shift towards disulfides, which could be considered an indicator of oxidative stress in rosacea.